Busch took the green-white-checkered finish after passing Joey Logano on the final lap of the chaotic race, which included 42 lead changes.
Ricky Stenhouse took second.
Busch's No. 1 Chevrolet was caught up in a major tangle on the 66th lap that was triggered by contact between Mike Wallace and Kevin Harvick. Busch had to pit repeatedly during the caution for emergency repairs that kept him in the race.
Among the drivers knocked out of the race was Danica Patrick, who led for 13 laps before spinning out on the 83rd of the scheduled 100 and again fell short of an elusive first NASCAR victory.
USA Today noted the big tangle on Lap 66 took out her drafting partners, and her later spinout sent her into the wall, damaging the steering column of her No. 7 Chevy, which had performed well enough in qualifying to start in the third spot in Friday's race.
Swim Week Miami Beach 2014 [PHOTOS]